Abstract

The cactus Opuntia ficus-indica is a xerophyte plant it has an increasing interest of nutritional and pharmacological power. In the present study we choose cactus cladode extract (CCE) to investigate its efficacy against benzo(a)pyrene (BAP) a widespread environmental genotoxin classified as probably carcinogenic to humans witch induced liver injury. Our results using balb/c mice clearly showed that BAP induced significant alterations in all tested oxidative stress markers the malondialdehyde level (MDA), the catalase activity and the expression of the heat shock proteins (Hsp 70) and (Hsp 27) which increased. In addition, it induces deoxyriboNucleic acid (DNA) fragmentation in liver and chromosomal aberrations in bone morrow cells. Moreover it increases the expression of anti apoptotic proteins bcl2 and decrease the expression of bax. The treatment of CCE after or before treatment with BAP showed a total reduction of BAP induced oxidative damage for all tested markers, it showed also an anti-genotoxic effect compared to the group treated with BAP alone, CCE was able to restrict the effect of BAP by differential modulation of the expression of p53 which is increased and its associated genes such as bax and bcl2. We concluded that CCE was effective in the protection against BAP hazards.

Key words: Cactus cladode extract, Benzo(a)pyrene, antioxidant activity,

anti-carcinogenicity, in vivo.

Abbreviation

CCE, Cactus cladode extract; BAP, benzo(a)pyrene; MDA, malondialdehyde level; Hsp 70, heat shock proteins 70; Hsp 27, heat shock proteins 27;DNA, deoxyriboNucleic acid; PAHs, polycyclic aromatic hydrocarbons; DMSO, dimethyl sulfoxide; NBT, nitro blue tetrazolium; BCIP, 5-bromo-4-chloro-3-indolyl phosphate disodium salt; H₂O, water; H₂O₂, hydrogen peroxide; TBA, thiobarbituric acid; TBARS, thiobarbituric acid-reactive substances; KCl, potassium chloride; UV, ultra violet; SD, standard deviation; ANOVA, analysis of variance; ROS, reactive oxygen species; EDTA, ethylene diamine tetraacetic acid; SDS, sodium dodecyl sulfate; DMSO, dimethylsulfoxide.